package com.wgcloud.util;

import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;

/**
 *
 * @ClassName:CodeUtil.java     
 * @version v2.3
 * @author: http://www.wgstart.com
 * @date: 2019年11月16日
 * @Description: 编码转换
 * @Copyright: 2019-2020 wgcloud. All rights reserved.
 *
 */
public class CodeUtil {
	/**
	 * 把SRC编码成uncode
	 * 方便AJAX传输
	 * @param src
	 * @return
	 */
	public static String escape(String src) {
		if(src==null)return src;
		int i;
		char j;
		StringBuffer tmp = new StringBuffer();
		tmp.ensureCapacity(src.length() * 6);
		for (i = 0; i < src.length(); i++) {
			j = src.charAt(i);
			if (Character.isDigit(j)
				|| Character.isLowerCase(j)
				
				|| Character.isUpperCase(j))
				tmp.append(j);
			else if (j < 256) {
				tmp.append("%");
				if (j < 16)
					tmp.append("0");
				tmp.append(Integer.toString(j, 16));
			} else {
				tmp.append("%u");
				tmp.append(Integer.toString(j, 16));
			}
		}
		return tmp.toString();
	}

	/**
	 * 把SRC解出正常编码
	 * 
	 * @param src
	 * @return
	 */
	public static String unescape(String src) {
		if(src==null)return src;
		StringBuffer tmp = new StringBuffer();
		
		tmp.ensureCapacity(src.length());
		int lastPos = 0, pos = 0;
		char ch;
		while (lastPos < src.length()) {
			pos = src.indexOf("%", lastPos);
			if (pos == lastPos) {
				if (src.charAt(pos + 1) == 'u') {
					ch =
						(char) Integer.parseInt(
							src.substring(pos + 2, pos + 6),
							16);
					tmp.append(ch);
					lastPos = pos + 6;
				} else {
					ch =
						(char) Integer.parseInt(
							src.substring(pos + 1, pos + 3),
							16);
					tmp.append(ch);
					lastPos = pos + 3;
				}
			} else {
				if (pos == -1) {
					tmp.append(src.substring(lastPos));
					lastPos = src.length();
				} else {
					tmp.append(src.substring(lastPos, pos));
					lastPos = pos;
				}
			}
		}
		return tmp.toString();
	}
	
	/**
	 * 前台解码
	 * @param src
	 * @return
	 */
	public static String decodeURIComponent(String src) {
		if(src==null)return src;
		String ret=null;
		try {
			ret = URLDecoder.decode(src,"utf-8");
		} catch (UnsupportedEncodingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return ret;
	}
	
	/**
	 * 双重编码
	 * @param data
	 * @return
	 */
	public static String dbEncode(String data){
		if(data==null)return null;
		return CodeUtil.escape(CodeUtil.encodeURIComponent(data));
	}
	
	/**
	 * 双重解码
	 * @param data
	 * @return
	 */
	public static String dbDecode(String data){
		if(data==null)return null;
		return CodeUtil.decodeURIComponent(CodeUtil.unescape(data));
	}
	
	/**
	 * 前台编码
	 * @param src
	 * @return
	 */
	public static String encodeURIComponent(String src) {
		if(src==null)return src;
		String ret=null;
		try {
			ret = URLEncoder.encode(src,"utf-8");
		} catch (UnsupportedEncodingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return ret;
		
	}
	
	/**
	 * HTML转为TEXT
	 * @param str
	 * @return
	 */
    public static String toText(String str){
	    if (str==null){
	    	return "";
	    }else{
			str=str.replaceAll("<", "&lt;");
			str=str.replaceAll(">", "&gt;");
			str=str.replaceAll("'", "''");
			str=str.replaceAll(" ", "&nbsp;");
			str=str.replaceAll("\n", "<br>");
			str=str.replaceAll("\"", "&#034;");
	    }
	    return str;
	}

    /**
     * TEXT转为HTML
     * @param str
     * @return
     */
	public static String toHtml(String str){
	    if (str==null){
	    	return "";
	    }else{
	    	str=str.replaceAll("&lt;", "<");
	    	str=str.replaceAll("&gt;", ">");
	    	str=str.replaceAll("''", "'");
	    	str=str.replaceAll("&nbsp;", " ");
	    	str=str.replaceAll("<br>", "\n");
			str=str.replaceAll("&#034;", "\"");
	    }
	    return str;
	}
	
	private static final char[] hexDigit = {
        '0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'
    };
   
    private static char toHex(int nibble) {
        return hexDigit[(nibble & 0xF)];
    }
	
	/**
     * 将字符串编码成 Unicode 。
     * @param theString 待转换成Unicode编码的字符串。
     * @param escapeSpace 是否忽略空格。
     * @return 返回转换后Unicode编码的字符串。
     */
    public static String toUnicode(String theString, boolean escapeSpace) {
        int len = theString.length();
        int bufLen = len * 2;
        if (bufLen < 0) {
            bufLen = Integer.MAX_VALUE;
        }
        StringBuffer outBuffer = new StringBuffer(bufLen);

        for(int x=0; x<len; x++) {
            char aChar = theString.charAt(x);
            // Handle common case first, selecting largest block that
            // avoids the specials below
            if ((aChar > 61) && (aChar < 127)) {
                if (aChar == '\\') {
                    outBuffer.append('\\'); outBuffer.append('\\');
                    continue;
                }
                outBuffer.append(aChar);
                continue;
            }
            switch(aChar) {
                case ' ':
                    if (x == 0 || escapeSpace) 
                        outBuffer.append('\\');
                    outBuffer.append(' ');
                    break;
                case '\t':outBuffer.append('\\'); outBuffer.append('t');
                          break;
                case '\n':outBuffer.append('\\'); outBuffer.append('n');
                          break;
                case '\r':outBuffer.append('\\'); outBuffer.append('r');
                          break;
                case '\f':outBuffer.append('\\'); outBuffer.append('f');
                          break;
                case '=': // Fall through
                case ':': // Fall through
                case '#': // Fall through
                case '!':
                    outBuffer.append('\\'); outBuffer.append(aChar);
                    break;
                default:
                    if ((aChar < 0x0020) || (aChar > 0x007e)) {
                        outBuffer.append('\\');
                        outBuffer.append('u');
                        outBuffer.append(toHex((aChar >> 12) & 0xF));
                        outBuffer.append(toHex((aChar >>   8) & 0xF));
                        outBuffer.append(toHex((aChar >>   4) & 0xF));
                        outBuffer.append(toHex( aChar         & 0xF));
                    } else {
                        outBuffer.append(aChar);
                    }
            }
        }
        return outBuffer.toString();
    }
   
    /**
     * 从 Unicode 码转换成编码前的特殊字符串。
     * @param in Unicode编码的字符数组。
     * @param off 转换的起始偏移量。
     * @param len 转换的字符长度。
     * @param convtBuf 转换的缓存字符数组。
     * @return 完成转换，返回编码前的特殊字符串。
     */
    public String fromUnicode(char[] in, int off, int len, char[] convtBuf) {
        if (convtBuf.length < len) {
            int newLen = len * 2;
            if (newLen < 0) {
                newLen = Integer.MAX_VALUE;
            }
            convtBuf = new char[newLen];
        }
        char aChar;
        char[] out = convtBuf;
        int outLen = 0;
        int end = off + len;

        while (off < end) {
            aChar = in[off++];
            if (aChar == '\\') {
                aChar = in[off++];
                if (aChar == 'u') {
                    // Read the xxxx
                    int value = 0;
                    for (int i = 0; i < 4; i++) {
                        aChar = in[off++];
                        switch (aChar) {
                        case '0':
                        case '1':
                        case '2':
                        case '3':
                        case '4':
                        case '5':
                        case '6':
                        case '7':
                        case '8':
                        case '9':
                            value = (value << 4) + aChar - '0';
                            break;
                        case 'a':
                        case 'b':
                        case 'c':
                        case 'd':
                        case 'e':
                        case 'f':
                            value = (value << 4) + 10 + aChar - 'a';
                            break;
                        case 'A':
                        case 'B':
                        case 'C':
                        case 'D':
                        case 'E':
                        case 'F':
                            value = (value << 4) + 10 + aChar - 'A';
                            break;
                        default:
                            throw new IllegalArgumentException(
                                    "Malformed \\uxxxx encoding.");
                        }
                    }
                    out[outLen++] = (char) value;
                } else {
                    if (aChar == 't') {
                        aChar = '\t';
                    } else if (aChar == 'r') {
                        aChar = '\r';
                    } else if (aChar == 'n') {
                        aChar = '\n';
                    } else if (aChar == 'f') {
                        aChar = '\f';
                    }
                    out[outLen++] = aChar;
                }
            } else {
                out[outLen++] = (char) aChar;
            }
        }
        return new String(out, 0, outLen);
    }
    
	
}
